如何快速构建高可用集群(Keepalived+Haproxy+Nginx)

转自次元立方网：http://www.it165.net/admin/html/201405/2957.html

 另一篇：HA-Proxy+Nginx实现web负载均衡（haproxy篇）http://www.it165.net/admin/html/201405/3171.html

 

• 组件及实现的功能

  Keepalived：实现对Haproxy服务的高可用，并采用双主模型配置;

  Haproxy：实现对Nginx的负载均衡和读写分离;

  Nginx：实现对HTTP请求的高速处理;

   

  架构设计图

  

   

  重点概念

  vrrp_script中节点权重改变算法

  vrrp_script 里的script返回值为0时认为检测成功，其它值都会当成检测失败；

  weight 为正时，脚本检测成功时此weight会加到priority上，检测失败时不加；

  主失败:

  主 priority < 从 priority + weight 时会切换。

  主成功：

  主 priority + weight > 从 priority + weight 时，主依然为主

  weight 为负时，脚本检测成功时此weight不影响priority，检测失败时priority – abs(weight)

  主失败:

  主 priority – abs(weight) < 从priority 时会切换主从

  主成功:

  主 priority > 从priority 主依然为主

  具体解释详见博文“Keepalived双主模型中vrrp_script中权重改变故障排查”

   

  部署配置

  Keepalived部署

  配置

  001. yum -yinstallkeepalived# 两节点都需部署

  002. # 172.16.25.109

  003. # vi /etc/keepalived/keepalived.conf

  004. ! Configuration Fileforkeepalived

  005. global_defs {

  006.    notification_email {

  007.          root@localhost

  008.    }

  009.    notification_email_from admin@lnmmp.com

  010.    smtp_connect_timeout 3

  011.    smtp_server 127.0.0.1

  012.    router_id LVS_DEVEL

  013. }

  014. vrrp_script chk_maintaince_down {

  015.    script"[[ -f /etc/keepalived/down ]] && exit 1 || exit 0"

  016.    interval 1

  017.    weight 2

  018. }

  019. vrrp_script chk_haproxy {

  020.     script"killall -0 haproxy"

  021.     interval 1

  022.     weight 2

  023. }

  024. vrrp_instance VI_1 {

  025.     interface eth0

  026.     state MASTER

  027.     priority 100

  028.     virtual_router_id 125

  029.     garp_master_delay 1

  030.     authentication {

  031.         auth_type PASS

  032.         auth_pass 1e3459f77aba4ded

  033.     }

  034.     track_interface {

  035.        eth0

  036.     }

  037.     virtual_ipaddress {

  038.         172.16.25.10/16 dev eth0 label eth0:0

  039.     }

  040.     track_script {

  041.         chk_haproxy

  042.     }

  043.     notify_master"/etc/keepalived/notify.sh master 172.16.25.10"

  044.     notify_fault"/etc/keepalived/notify.sh fault 172.16.25.10"

  045. }

  046. vrrp_instance VI_2 {

  047.     interface eth0

  048.     state BACKUP

  049.     priority 99

  050.     virtual_router_id 126

  051.     garp_master_delay 1

  052.     authentication {

  053.         auth_type PASS

  054.         auth_pass 7615c4b7f518cede

  055.     }

  056.     track_interface {

  057.        eth0

  058.     }

  059.     virtual_ipaddress {

  060.         172.16.25.11/16 dev eth0 label eth0:1

  061.     }

  062.     track_script {

  063.         chk_haproxy

  064. chk_maintaince_down

  065.     }

  066.     notify_master"/etc/keepalived/notify.sh master 172.16.25.11"

  067.     notify_backup"/etc/keepalived/notify.sh backup 172.16.25.11"

  068.     notify_fault"/etc/keepalived/notify.sh fault 172.16.25.11"

  069. }

  070. # 172.16.25.110

  071. # vi /etc/keepalived/keepalived.conf

  072. ! Configuration Fileforkeepalived

  073. global_defs {

  074.    notification_email {

  075.          root@localhost

  076.    }

  077.    notification_email_from admin@lnmmp.com

  078.    smtp_connect_timeout 3

  079.    smtp_server 127.0.0.1

  080.    router_id LVS_DEVEL

  081. }

  082. vrrp_script chk_maintaince_down {

  083.    script"[[ -f /etc/keepalived/down ]] && exit 1 || exit 0"

  084.    interval 1

  085.    weight 2

  086. }

  087. vrrp_script chk_haproxy {

  088.     script"killall -0 haproxy"

  089.     interval 1

  090.     weight 2

  091. }

  092. vrrp_instance VI_1 {

  093.     interface eth0

  094.     state BACKUP

  095.     priority 99

  096.     virtual_router_id 125

  097.     garp_master_delay 1

  098.     authentication {

  099.         auth_type PASS

  100.         auth_pass 1e3459f77aba4ded

  101.     }

  102.     track_interface {

  103.        eth0

  104.     }

  105.     virtual_ipaddress {

  106.         172.16.25.10/16 dev eth0 label eth0:0

  107.     }

  108.     track_script {

  109.         chk_haproxy

  110. chk_maintaince_down

  111.     }

  112.     notify_master"/etc/keepalived/notify.sh master 172.16.25.10"

  113.     notify_backup"/etc/keepalived/notify.sh backup 172.16.25.10"

  114.     notify_fault"/etc/keepalived/notify.sh fault 172.16.25.10"

  115. }

  116. vrrp_instance VI_2 {

  117.     interface eth0

  118.     state MASTER

  119.     priority 100

  120.     virtual_router_id 126

  121.     garp_master_delay 1

  122.     authentication {

  123.         auth_type PASS

  124.         auth_pass 7615c4b7f518cede

  125.     }

  126.     track_interface {

  127.        eth0

  128.     }

  129.     virtual_ipaddress {

  130.         172.16.25.11/16 dev eth0 label eth0:1

  131.     }

  132.     track_script {

  133.         chk_haproxy

  134.     }

  135.     notify_master"/etc/keepalived/notify.sh master 172.16.25.11"

  136.     notify_backup"/etc/keepalived/notify.sh backup 172.16.25.11"

  137.     notify_fault"/etc/keepalived/notify.sh fault 172.16.25.11"

  138. }

  139. # vi /etc/keepalived/notify.sh

  140. #!/bin/bash

  141. # Author: Jason.Yu <admin@lnmmp.com>

  142. # description: An example of notify script

  143. #

  144. contact='root@localhost'

  145. notify() {

  146.     mailsubject="`hostname` to be $1: $2 floating"

  147.     mailbody="`date '+%F %H:%M:%S'`: vrrp transition, `hostname` changed to be $1"

  148.     echo$mailbody | mail -s "$mailsubject"$contact

  149. }

  150. case"$1"in

  151.     master)

  152.         notify master $2

  153.         /etc/rc.d/init.d/haproxy restart

  154.         exit0

  155.     ;;

  156.     backup)

  157.         notify backup $2# 在节点切换成backup状态时，无需刻意停止haproxy服务，防止chk_maintaince和chk_haproxy多次对haproxy服务操作；

  158.         exit0

  159.     ;;

  160.     fault)

  161.         notify fault $2# 同上

  162.         exit0

  163.     ;;

  164.     *)

  165.         echo'Usage: `basename $0` {master|backup|fault}'

  166.         exit1

  167.     ;;

  168. esac

  启动服务

  1. service keepalived start# 在两个节点上都需要启动

  keepalived双主模型启动

  

  Haproxy部署

  安装配置

  01. yum -yinstallhaproxy# 两节点都需部署

  02. vi/etc/haproxy/haproxy.cfg# 两节点配置一致

  03. global

  04.     log         127.0.0.1 local2

  05.     chroot      /var/lib/haproxy

  06.     pidfile     /var/run/haproxy.pid

  07.     maxconn     4000

  08.     user         haproxy

  09.     group       haproxy

  10.     daemon# 以后台程序运行；

  11. defaults

  12.     mode                   http# 选择HTTP模式，即可进行7层过滤；

  13.     log                     global

  14.     option                  httplog# 可以得到更加丰富的日志输出；

  15.     option                  dontlognull

  16.     option http-server-close# server端可关闭HTTP连接的功能；

  17.     option forwardfor except 127.0.0.0/8# 传递client端的IP地址给server端，并写入“X-Forward_for”首部中；

  18.     option                  redispatch

  19.     retries                 3

  20.     timeout http-request    10s

  21.     timeout queue           1m

  22.     timeout connect         10s

  23.     timeout client          1m

  24.     timeout server          1m

  25.     timeout http-keep-alive 10s

  26.     timeout check           10s

  27.     maxconn                 30000

  28. listen stats

  29.     modehttp

  30.     bind0.0.0.0:1080# 统计页面绑定1080端口；

  31.     statsenable# 开启统计页面功能；

  32.     stats hide-version# 隐藏Haproxy版本号；

  33.     stats uri     /haproxyadmin?stats# 自定义统计页面的访问uri；

  34.     stats realm   Haproxy\ Statistics# 统计页面密码验证时的提示信息；

  35.     stats auth    admin:admin# 为统计页面开启登录验证功能；

  36.     stats adminifTRUE# 若登录用户验证通过，则赋予管理功能；

  37. frontend http-in

  38.     bind*:80

  39.     mode http

  40.     log global

  41.     option httpclose

  42.     option logasap

  43.     option dontlognull

  44.     capture request  header Host len 20

  45.     capture request  header Referer len 60

  46.     acl url_static       path_beg       -i /static /images /javascript /stylesheets

  47.     acl url_static       path_end       -i .jpg .jpeg .gif .png .css .js .html

  48.     use_backend static_serversifurl_static# 符合ACL规则的，请求转入后端静态服务器

  49.     default_backend dynamic_servers# 默认请求转入后端动态服务器

  50. backend static_servers

  51.     balance roundrobin

  52.     server imgsrv1 192.168.0.25:80 check maxconn 6000# 静态服务器，可配置多台，还可设置权重weight；

  53. backend dynamic_servers

  54.     balancesource# 对于动态请求利用source调度算法，可一定程度上实现session保持；但最好利用cookie绑定的方式实现session保持

  55.     server websrv1 192.168.0.35:80 check maxconn 1000# 动态服务器，可配置多台，还可设置权重weight；

  启动服务

  1. service haproxy start# 两节点都需要启动

  Nginx部署

  见博客“如何测试Nginx的高性能”http://www.it165.net/admin/html/201405/2928.html

   

  访问验证

  Haproxy统计页面测试

  

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  动静分离测试

   

  

  

  高可用测试